05000267/LER-1980-074-03, /03L-0:on 801210,pilot Valve in Fixed Water Spray Sys Resulted in Control Room Alarm.Caused by Leakage Past Pilot Valve Seat Due to Corrosion & Settling of Sediment from Fire Water.Corrosion Removed

/03L-0:on 801210,pilot Valve in Fixed Water Spray Sys Resulted in Control Room Alarm.Caused by Leakage Past Pilot Valve Seat Due to Corrosion & Settling of Sediment from Fire Water.Corrosion Removed

ML19340E479
Person / Time
Site:	Fort Saint Vrain
Issue date:	01/09/1981
From:	Gahm J PUBLIC SERVICE CO. OF COLORADO
To:	NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML19340E477	List: 05000267/LER-1980-074, Forwards LER 80-074/03L-0 05000267/LER-1980-074-03, /03L-0:on 801210,pilot Valve in Fixed Water Spray Sys Resulted in Control Room Alarm.Caused by Leakage Past Pilot Valve Seat Due to Corrosion & Settling of Sediment from Fire Water.Corrosion Removed
References
LER-80-074-03L, LER-80-74-3L, NUDOCS 8101140646
Download: ML19340E479 (4)

LER-1980-074, /03L-0:on 801210,pilot Valve in Fixed Water Spray Sys Resulted in Control Room Alarm.Caused by Leakage Past Pilot Valve Seat Due to Corrosion & Settling of Sediment from Fire Water.Corrosion Removed

Event date:
Report date:
2671980074R03 - NRC Website

text

N*4 )ORM 366 U. S. NUCLE A2 REGULATORY COMMISSION LICENSEE EVENT REPORT CONTROL BLOCK: l l

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l IPLE ASE PRINT OR TYPE ALL REQUIRED INFORMATIONI e

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'S RE*0RT D ATE 80 EVENT CESCRIPTION AND PROSA8LE CONSEQUENCES h loI:l l During normal operation. the fixed water sprav system for the Auxiliary Boiler unnm I

g o,3 ; l vas taken out of service for repair of a pilot vilve. which was causine a nuisance io ;4 l l alarm in the Control Room. This resulted in operation in a degraded mode oernitted I

io!3j l by LCO 4.10.5 and is reportable per Fort St. Vrain ""echnical Specification AC 7.5.2(bh2.

I o !61 1 There was no affect on public health or safety. No accompanying occurrence. No re-l l3j,j l lated reports.

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40 41 42 43 44 47 CAUSE OESCRIPTION AND CORRECTIVE ACTIONS h l i ; o ! l The nuisance alarm was caused by leakage past the pilot valve seat. due to normal l

l3 iii l corrosion and settling of sediment from the fire water. The corrosion was removed I

l from the valve and the valve and system were returned to service. Valve is an l

,, ;3, l Auto =atic Sprinkler Corporation Model #153. Retard chamber is a Model A-2.

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I REPORT DATE:

Januarv 9,1981 REPORTABLE OCCURRENCE 80-074 ISSUE O OCCURRENCE DATE:

December 10, 1980 Page 1 of 3 FmT ST. VRAIN NUCLEAR GENERATING STATION PUBLIC SERVICE COMPANY OF COLORADO 16805 WE1D COUNTY ROAD 191/2 PLATTEVILLE, COLORADO 80651 REPORT No. 50-267/80-074/03-L-0 Final IDENTIFICATION OF OCCURRENCE:

A fixed water spray system required to be operable during power operation was removed from service for repair of a pilot valve. This is operation in a degraded mode permitted by LCO 4.10.5 and is reportable per Fort St. Vrain Technical Specification AC 7.5.2(b)2.

EVENT

DESCRIPTION

On December 10, 1980, while operating at 69% thermal power and 215 MW elec-l trical power, the auxiliary boiler room fixed water spray fire protection system was taken out of service f or repair of a leaky pilot valve, which l

was causing a nuisance alarm in the Control Room. The fixed spray system was taken out of service at 1515 hours0.0175 days <br />0.421 hours <br />0.0025 weeks <br />5.764575e-4 months <br /> on December 10, 1980, and returned l

co service at 1330 hours0.0154 days <br />0.369 hours <br />0.0022 weeks <br />5.06065e-4 months <br /> on December 11, 1980. The areas were inspected on an hourly basis and backup fire fighting equipment was available ad-jacent to the auxiliary boiler room.

CAUSE

DESCRIPTION:

See Fi re 1.

The nuisance al was caused by water leaking past the pilot valve of the alarm valve The normal corrosion due to standing water a settling of sediment rom th fire water produced a bad sea that allowed leakage past the pilot valve 1 into the retarding chamber 3 and produced the nuisance alarm. Sediment and corrosion were removed from the pilot valve seat and the clapper valve hinge pin ($).

CORRECTIVE ACTION:

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The pilot valve was repaired and the fixed water spray system returned to s ervic e, l

i No further corrective action anticipated or required.

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REPCRIABLE OCCL*RRENCE 80-07/.

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l REPORTABLE OCCURRENCE 80-074 ISSUE O Pa ge 3 of 3 Prepared By:

Asa B. Reed Technical Services Technician Reviewed By:

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Frank M. Mathie Operations Manager Approved By:

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Don '4arembourg gf Manager, Nuclear Production 4

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